SpringMVC学习 通过注解和非注解的方式配置控制器，适配器，映射器

一：注解式的

@Controller
public class ItemsController2 {
    //制定访问(映射)的url
    //我对映射器的理解，感觉它就相当于与一个servlet
    @RequestMapping("/queryList")
    public ModelAndView getList() {
        System.out.println("ItemsController2");
        List<Items> list = new ArrayList<>();
        Items items1 = new Items();
        items1.setName("电脑");
        items1.setPrice(6000f);
        items1.setDetail("联想 Y700");

        Items items2 = new Items();
        items2.setName("手机");
        items2.setPrice(3000f);
        items2.setDetail("HuaWei Mate20");
        list.add(items1);
        list.add(items2);

        //定义modelAndView
        ModelAndView modelAndView = new ModelAndView();
        //向modelAndView中添加对象，相当于request中的setAttribute
        modelAndView.addObject("ItemsList", list);
        //指定视图
        modelAndView.setViewName("items/itemsList");
        return modelAndView;
    }


}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--用来扫描controller层的包-->
    <context:component-scan base-package="controller"></context:component-scan>

    <!--用来加载MVC提供的映射器和适配器，而且还相较于传统的类加载，这种方式还提供了很多的自定义绑定参数-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--加载视图处理器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
</beans>

二：非注解式的

public class ItemsController implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
        List<Items> list = new ArrayList<>();

        Items items1 = new Items();
        items1.setName("电脑");
        items1.setPrice(6000f);
        items1.setDetail("联想 Y700");

        Items items2 = new Items();
        items2.setName("手机");
        items2.setPrice(3000f);
        items2.setDetail("HuaWei Mate20");

        list.add(items1);
        list.add(items2);
        //定义modelAndView
        ModelAndView modelAndView = new ModelAndView();
        //向modelAndView中添加对象，相当于request中的setAttribute
        modelAndView.addObject("ItemsList", list);
        //指定视图
        modelAndView.setViewName("items/itemsList");
        return modelAndView;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!--
    配置Handler
    通过'name'指定访问的url 通过class 指定被访问的class
    -->
    <bean name="/itemsController.action" class="controller.ItemsController"></bean>

    <!--
        配置处理器的映射器 HandlerMapping
        将Bean的name作为Url进行查找，需要在配置Handler时指定beanname
        -->
    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>

    <!--
        配置处理器适配器
        所有适配器都实现controller接口
        -->
    <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>

    <!--
    配置视图解析器
    需要配置解析jsp的视图解析器,默认使用jstl标签
    -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"></bean>
</beans>

三：两者通用的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <!--context-param可以在web工程发布之前对参数进行初始化，而且他的范围大，整个web工程都能共享他内部的数据-->
    <!--contextConfigLocation 和 ContextLoaderListener 由SpringMVC进行识别处理 能够加载配置文件，
    当然也可以自定义context-param
    -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--配置一个servlet 加载DispatcherServlet类，表示声明为一个前置控制器-->
    <servlet>
        <servlet-name>annotationDispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--init-param 标签和context-param标签的区别主要在于作用范围，前者只适用于在servlet内部，后者则是全局-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <!--通过‘；’分号分隔符，可以实现对多个配置文件的加载-->
            <param-value>
                classpath:*.xml;
                /WEB-INF/*-servlet.xml
            </param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>annotationDispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>